The goal of the training grant is to build research capacity to identify strategies and devise means to interrupt the cycle of transmission and pathogenesis of leishmaniasis through intervention of the invertebrate and vertebrate host pathogen interactions. To achieve this goal, the training program will implement research capacity in the molecular analysis of the interaction between Leishmania and both the sandfly vector and the mammalian host. The proposed program builds upon the existing research capacity and ongoing projects of the developing country institution in clinical, epidemiological and biological aspects of cutaneous and visceral leishmaniasis and other transmissible diseases, prior collaboration with Yale faculty, and the critical mass of faculty and infrastructure for the conduct of molecular analyses of kinetoplastid parasites and host responses available at Yale University. Colombian scientists will receive training at Yale through the conduct of mentored research, auditing of postgraduate courses and short courses on research skills, such as biosafety, responsible conduct of research, and scientific writing. Workshops will be offered each year at CIDEIM with the participation of Yale Faculty (on site and teleconferencing) to build and multiply research skills and introduce national investigators to concepts and principles of molecular analysis (bioinformatics and data mining, functional genomics, expression analysis). Predoctoral trainees will be selected among postgraduate students from Colombian universities who conduct thesis research in CIDEIM. Students will be recent graduates of human or veterinary medicine and basic science who have qualified for scholarship support within the framework of COLCIENCIAS'Young Investigator program. Post-doctoral training and scientific exchange for periods of up to 4 months will be available to research staff of CIDEIM whose research is relevant to the vector or host- Leishmania interaction. During year 5 of the program, formal postgraduate courses on the molecular genetic analyses of host (mammalian/vector)-pamsite interactions will be offered to national and regional students by CIDEIM. Overall, the training conducted will prepare investigators in new areas of research, implement training by teleconferencing, and assure the capacity to offer formal courses for Colombian and regional post-graduate students. All of these will contribute to the sustainability of research capacity.